scholarly journals The Effects of Aluminium Sulphate on Slag Paste Activated with Sodium Hydroxide and Sodium Silicate

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2286
Author(s):  
Taewan Kim ◽  
Sungnam Hong ◽  
Choonghyun Kang
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Sodium Hydroxide ◽  
Blast Furnace Slag ◽  
Aluminium Sulphate ◽  
The Third ◽  
Granulated Blast Furnace Slag ◽  
Activated Slag ◽  
Furnace Slag ◽  
Alkali Activated

This study investigates the characteristics of alkali-activated slag cement using aluminium sulphate (ALS) as an activator. The alkalis NaOH and Na2SiO3 were used as additional activators (denoted by alkali) at 5% and 10% of the weight of the ground granulated blast furnace slag (GGBFS). Three types of activators were considered. The first was when ALS was used alone. For the second, ALS and 5% alkali were used together. The third was when ALS and 10% alkali were used. ALS was used at concentrations of 2%, 4%, 6%, 8%, and 10% based on binder weight. Experimental results show that when ALS was used as a sole activator, the activity of GGBFS was low and its strength was below 1 MPa. However, compressive strength was improved when 5% or 10% alkali and ALS were used at the same time. This was effective at improving mechanical and microstructural performance when used with an additional activator capable of forming a more alkaline environment than using ALS as a sole activator.

Effect of Sodium Hydroxide (NaOH) Concentration on Compressive Strength of Alkali-Activated Slag (AAS) Mortars

2015 ◽  
Vol 754-755 ◽  
pp. 300-304 ◽  
Author(s):  
Aimi Noorliyana Hashim ◽  
Kamarudin Hussin ◽  
Noorzahan Begum ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamrosni Abdul Razak ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Sodium Hydroxide ◽  
Blast Furnace Slag ◽  
Alkali Activated Slag ◽  
Granulated Blast Furnace Slag ◽  
Environmental Friendly ◽  
Activated Slag ◽  
Furnace Slag ◽  
Alkali Activated

Energy saving in building technology is among the most critical problems in the world. Thus it is a need to develop sustainable alternatives to conventional concrete utilizing more environmental friendly materials. One of the possibilities to work out is the massive usage of industrial wastes like ground granulated blast furnace slag (GGBS) to turn them to useful environmental friendly and technologically advantageous cementitious materials. In this study, ground granulated blast furnace slag (GGBS) is used to produce of alkali activated slag (AAS) mortar with the effect of alkaline activator concentration. Alkali activated slag (AAS) mortar is accelerated using alkaline solution of sodium silicate mixed with sodium hydroxide. The fixed ratio of sodium silicate to sodium hydroxide is 1.7 and the concentration of sodium hydroxide is varied from 6M to 12M. Concentration of 10M NaOH promotes the best properties of mortar by achieving the greatest compressive strength. Substitution of mineral admixture also influences strength performance of AAS mortars. The mortar with 20% calcium carbonate demonstrates the maximum compressive strength. The used of alkaline activation system is the best method to prepare industrial byproduct concrete. Moreover, alkali activated product itself gains superior properties which lead to the system become the most interesting method to produce sustainable concrete.

Experimental Study on Compound Binding Material of Alkali Activated Metakaolin and Ground Granulated Blast Furnace Slag

2011 ◽  
Vol 287-290 ◽  
pp. 1275-1279
Author(s):  
Yong Jia He ◽  
Lin Nu Lu ◽  
Shu Guang Hu
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Hydration Product ◽  
Alkali Activation ◽  
Granulated Blast Furnace Slag ◽  
Binding Material ◽  
Measurement Results ◽  
Furnace Slag ◽  
Alkali Activated

Compound binding material was prepared by the alkali activation of metakaolin and ground granulated blast furnace slag. Hydration product components, microstructure and mechanical properties of the hardened paste were investigated by IR, XRD, SEM, MIP, and compressive strength measurement. Results indicated that hydration products included C-S-H and geopolymer, and both of them were amorphous although there were differences in their structure and morphology. When the dosage of slag was less than 50%, the compressive strength of hardened paste increased as the dosage increased, which was mainly because C-S-H produced by the reaction of GGBFS and alkali filled void in geopolymer phase, and part of unreacted slag particles acting as microaggregate to prevent from extension of microcrack in the hardened paste, so the porosity of hardened paste decreased and compressive strength increased.

Effect of the Combined Using of Fly Ash and Granulated Blast Furnace Slag on Properties of Cementless Alkali-Activated Mortar

2011 ◽  
Vol 287-290 ◽  
pp. 916-921
Author(s):  
Kyung Taek Koh ◽  
Gum Sung Ryu ◽  
Si Hwan Kim ◽  
Jang Hwa Lee
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Curing Temperature ◽  
Mixture Ratio ◽  
Granulated Blast Furnace Slag ◽  
Alkaline Activator ◽  
Furnace Slag ◽  
Alkali Activated

This paper examines the effects of the mixture ratio of fly ash/slag, the type of alkaline activators and curing conditions on the workability, compressive strength and microstructure of cementless alkali-activated mortar. The investigation showed that the mixture ratio of fly ash/slag and the type of alkaline activator have significant influence on the workability and strength, whereas the curing temperature has relatively poor effect. An alkali-activated mortar using a binder composed of 50% of fly ash and 50% of granulated blast furnace slag and alkaline activator made of 9M NaOH and sodium silicate in proportion of 1:1 is seen to be able to develop a compressive strength of 65 MPa at age of 28 days even when cured at ambient temperature of 20°C.

Properties of Alkali Activated Ground Granulated Blast Furnace Slag Based Geopolymers

2017 ◽  
Vol 1143 ◽  
pp. 114-119
Author(s):  
Ilenuta Severin ◽  
Maria Vlad
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Sodium Hydroxide ◽  
Wheat Straw ◽  
Red Mud ◽  
Blast Furnace Slag ◽  
Negative Impact ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag ◽  
Straw Ash

Ground granulated blast furnace slag, red mud, wheat straw ash are secondary material which after alkaline activation can be used in the construction materials’ domain. Their disposal poses a threat to the environment, whereas by reusing them we would be able to reduce this negative impact. This paper describes the research carried out in order to synthesise some geopolymer recipes, which are based on ground granulated blast furnace slag, red mud and wheat straw ash, alkaline activated with sodium hydroxide or a solution made with sodium hydroxide and sodium silicate. Factors that influence the compression strength have been studied such as: the nature of the alkaline activator, the chemical composition of solid materials in the recipes and the curing time. The geopolymer samples have been dried at room temperature for 7 and 28 days, respectively, and after the compressive strength tests has been made. Following this research it has been found out that NaOH/Na2SiO3 activated geopolymer samples have shown a higher resistance in the compressive strength. From the SEM analysis it has been found out that the samples with a higher amount of ground granulated blast furnace slag in their composition had a more homogeneous and less porous design than those with a smaller amount of ground granulated blast furnace slag.

The Influence of the Properties of the Material Used for Obtaining Geopolymers on Their Structure and Compressive Strength

2017 ◽  
Vol 68 (6) ◽  
pp. 1182-1187
Author(s):  
Ilenuta Severin ◽  
Maria Vlad
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Wheat Straw ◽  
Red Mud ◽  
Blast Furnace Slag ◽  
Complex Structure ◽  
Point Of View ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag ◽  
Straw Ash

This article presents the influence of the properties of the materials in the geopolymeric mixture, ground granulated blast furnace slag (GGBFS) + wheat straw ash (WSA) + uncalcined red mud (RMu), and ground granulated blast furnace slag + wheat straw ash + calcined red mud (RMc), over the microstructure and mechanical properties of the synthesised geopolymers. The activation solutions used were a NaOH solution with 8M concentration, and a solution realised from 50%wt NaOH and 50%wt Na2SiO3. The samples were analysed: from the microstructural point of view through SEM microscopy; the chemical composition was determined through EDX analysis; and the compressive strength tests was done for samples tested at 7 and 28 days, respectively. The SEM micrographies of the geopolymers have highlighted a complex structure and an variable compressive strength. Compressive strength varied from 24 MPa in the case of the same recipe obtained from 70% of GGBFS + 25% WSA +5% RMu, alkaline activated with NaOH 8M (7 days testing) to 85 MPa in the case of the recipe but replacing RMu with RMc with calcined red mud, alkaline activated with the 50%wt NaOH and 50%wt Na2SiO3 solution (28 days testing). This variation in the sense of the rise in compressive strength can be attributed to the difference in reactivity of the materials used in the recipes, the curing period, the geopolymers structure, and the presence of a lower or higher rate of pores, as well as the alkalinity and the nature of the activation solutions used.

scholarly journals Red Mud-Blast Furnace Slag-Based Alkali-Activated Materials

2021 ◽  
Vol 13 (20) ◽  
pp. 11298
Author(s):  
Alessio Occhicone ◽  
Mira Vukčević ◽  
Ivana Bosković ◽  
Claudio Ferone
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Red Mud ◽  
Blast Furnace Slag ◽  
Bauxite Residue ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Waste Products ◽  
Furnace Slag ◽  
Alkali Activated

The aluminum Bayer production process is widespread all over the world. One of the waste products of the Bayer process is a basic aluminosilicate bauxite residue called red mud. The aluminosilicate nature of red mud makes it suitable as a precursor for alkali-activated materials. In this work, red mud was mixed with different percentages of blast furnace slag and then activated by sodium silicate solution at different SiO2/Na2O ratios. Obtained samples were characterized by chemical–physical analyses and compressive strength determination. Very high values of compressive strength, up to 50 MPa, even for high percentage of red mud in the raw mixture (70 wt.% of RM in powder mixture), were obtained. In particular, the higher compressive strength was measured for cubic samples containing 50 wt.% of RM, which showed a value above 70 MPa. The obtained mixtures were characterized by no or scarce environmental impact and could be used in the construction industry as an alternative to cementitious and ceramic materials.

scholarly journals Effect of Na2SiO3/Naoh on the Compressive Strength of Inorganic Polymer Concrete Mixed with Ground Granulated Blast Furnace Slag (GGBS) At Ambient Condition

2019 ◽  
Vol 9 (2) ◽  
pp. 1222-1228
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Ambient Condition ◽  
Polymer Concrete ◽  
Geopolymer Concrete ◽  
Split Tensile Strength ◽  
Standard Size ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

This paper aims to investigate the influence of alkaline activators solution i.e, Na2SiO3 / NaOH on compressive strength of geopolymer concrete mixed with Ground Granulated Blast furnace slag (GGBS) for constant molarity 8 M. The ratio of alkali to binder ratio is taken as 0.5 and the ratio of Na2SiO3 / NaOH is 2.5. The geopolymer mix is based on pervious sutdies. As per Indian standard size moulds for the cube, cylinder and prism are cast, cured and tested.The specimens were tested for fresh concrete properties such as slump cone test and hardened properties such as compressive strength for cubes, split tensile strength for cylinders and flexural strength for prism different days of curing under ambient temperature. Also, a microstructural study is done by using Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX) for the tested sample. It is found from the test results that, with the aid of alumino-silicate solution, early strength is achieved by geopolymer concrete within 7 days under ambient condition due to the presence of ground granulated slag.

Sign in / Sign up

Export Citation Format

Share Document